It's a love/ hate thing for me....I didn't start smoking until late in my 20's - dumb,eh?
I smoke menthol and am a total hedonist with my first cup of strong coffee and a smoke in the morning...I review my day ahead mentally, etc. In business the smoke break is a time out to stop, evaluate and decide before I re-enter the fray. If I'm on the phone or out having a glass of wine with friends I smoke.
I haven't quit/quit but the two and three year breaks were probably a good thing. What I do know regarding the weight thing is your body works more efficiently when you stop and you have to start burning 300 calories more a day at minimum.
I can't stand cigarettte smoke, mine or anyone elses - I don't smoke in my house and I don't smoke in any of my vehicles.
My only advice Nan is to be aware of your smoking. I keep my cigs in another room so I have to stop what I'm doing, go and fetch them before heading outside. This helps with the mindless smoking so many of us do
P.S. - when my non-smoking friends give me a hard time (because they love me) I point out that I power walk three miles a day, eat fast food less than 3 times a year, weigh less than 10 pounds more than when I was in college and have low cholestrol and blood pressure